Synthesis and characterization of chloro-sulphide glass-ceramics containing neodymium(III) ions

In this paper, we describe the preparation of Nd³⁺ doped glass-ceramics in the (GeS₂)₇₀-(Ga₂S₃)₂₀-(CsCl)₁₀ system. Neodymium has been introduced as metallic powder or incorporated as sulphide. Appropriate heat treatments of the base-glass lead to glass-ceramics with controllable crystal sizes that are transparent in the visible and infrared spectral ranges. X-ray diffraction as well as electron diffraction techniques were used to investigate the crystallization process. Differential scanning calorimetry indicates that neodymium ions are poor nucleating agents in this glass compared to erbium ions. Luminescence measurements were also performed and point out that although the ceramization process increases significantly the luminescence efficiency, the neodymium ions are only partially incorporated in the nanocrystals.     

Stretching and breaking of a molecular junction

Density functional theory (DFT) calculations based on band structure are used to investigate the electromechanical properties of a molecular junction consisting of a dithiolbenzene molecule sandwiched between two gold slabs. This represents a prototypical system for the field of molecular electronics; such a system has previously been studied in break-junction measurements and electron-transport calculations. The stretching and breaking behavior of the junction is analyzed for different geometric conformations, and it is found that the breakage occurs through dissociation of one of the sulfur-gold bonds with a maximum force of 1.25 nN. The molecular electronic states shift during stretching, and, at the point of highest stress in the junction, the highest occupied molecular orbital (HOMO) of the molecule is located exactly at the Fermi level.     

Aging and inhibition processes: The case of metaphor treatment.

The inhibitory deficit hypothesis has often been cited as a possible explanation for cognitive changes related to age. The aim of this study was to develop a new procedure for evaluating effortful inhibition on the basis of the comprehension of metaphors. Our experiment was carried out on younger and older adults, in whom we also measured inhibitory capacity, working memory, and processing speed. The results show that older participants required a longer time and made more frequent errors in rejecting metaphors versus literally false statements. The interference effect was predicted by the psychometric tests designed to evaluate inhibition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

L'Amor?age affectif: Données empiriques et modèles théoriques.

The automaticity of evaluative processing is one of the most important issues in cognitive psychology of emotions. The affective priming paradigm has been created specifically in order to provide some evidence regarding this issue. For 20 years, this paradigm has resulted in a significant number of studies. Originally focused on the automaticity of evaluation, investigation rapidly moved to the underlying mechanisms and it has led to a theoretical dichotomy. Some studies suggest that a spreading activation mechanism underlies affective priming effects, whereas other studies suggest that this priming effect is determined by a response competition mechanism similar to that found in compatibility tasks such as the Stroop task. The clarification of the theoretical models of affective priming therefore appears to be necessary in order to improve the understanding of the effect, possibly leading to its justified use as an indirect measure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phototransformation of water-soluble polymers. Part II: photooxidation of poly(ethylene oxide) in aqueous solution

Poly(ethylene oxide) (PEO) was irradiated in aqueous solution under long wavelengths (λ>300 nm, 20 °C) and in presence of oxygen. The photooxidation of PEO was studied by IR spectrophotometry, viscometry and size exclusion chromatography. The formation of the oxidation photoproducts was studied by infrared analysis of films obtained by evaporation of aliquots of irradiated aqueous solutions. The photoproducts were identified by chemical derivatization treatments coupled with infrared measurements. Viscosimetry and SEC analysis showed that photooxidation was leading to a dramatic decrease of the molecular weights. The influence of the pH of the aqueous solutions was also examined. Unexpected results were obtained for the pH 12 solutions, indicating a strong inhibition of the oxidation.

Comparison with the results obtained in the case of PEO irradiated in the solid state showed that no direct transposition of the knowledge concerning the behavior of the solid polymer could be made.     

Yeast sequencing reports. CAN1, a gene encoding a permease for basic amino acids in Candida albicans

The first gene coding for an amino-acid permease of Candida albicans was sequenced. The DNA fragment complementing the lysine-permease deficiency was 3385 bp long. An open reading frame of 1713 nucleotides was found encoding a protein of 571 amino acids, with a calculated molecular weight of 63 343. Analysis of the deduced primary structure revealed ten membrane spanning regions and three potential N-glycosylation sites. The protein sequence is strongly homologous to both permeases for basic amino acids (Can1 and Lyp1) of Saccharomyces cerevisiae. C-terminal part of another ORF (105 aa), highly homologous to the gene HAL2 of S. cerevisiae, was found 133 bp downstream, and in tail-to-tail orientation to the permease gene. The sequence data will appear in the EMBL/GenBank/DDBJ Nucleotide Sequence Data Libraries under the accession number X76689.     

Multiresolution in astronomical image processing: A general framework

Multiresolution transforms, including a wavelet transform, are applied simage visualization, image restoration, filtering and compression, × object detection. Variance stabilization is used, when appropriate, cater for common astronomical image noise models. We discuss idation of such methods in the case of astronomical image processing. A range of examples illustrate the effectiveness of this aproach in handling point source and extended astronomical objects.